PAD is a manifestation of systemic atherosclerosis, characterized by atherosclerotic blockages ofthe arteries supplying the legs. Claudication, defined as walking induced gait dysfunction and muscle pain, is the most common manifestation of PAD. Claudication affects 5% of Americans older than 55 years of age. Claudicating patients experience reduced mobility, reduced physical functioning, poor health outcomes, and increased risk for falls. To investigate the mobility issues in patients with PAD, Dr. Myers, the PI of this research project, has assessed lower extremity function by measuring amount (standard deviation and coefficient of variation) and temporal structure (largest Lyapunov exponent, sample entropy) of the stride-tostride fluctuations that exist during walking or simply termed gait variability. Such measures are emerging as important investigative tools to study clinical gait disorders, as they are predictors of falls and reflect individuals' capabilities to adapt within the movement environment. Dr. Myers' studies show that patients with PAD have altered gait variability as compared with healthy age-matched controls. Thus, this research project will utilize gait variability to determine the impact of common PAD related pathologies as well as determine if gait variability can predict clinical disease parameters (hemodynamics, walking distance, quality of life) at baseline and following surgical revascularization. The central hypothesis is that gait variability is indicative of lower extremity health outcomes and could guide clinical decision-making. Gait variability can establish the impact of PAD-related pathologies (diabetes and non-healing, shallow ulcers) on lower extremity function in patients. Determining which gait variability parameter is the best predictor of clinical disease parameters and of lower extremity function improvements post-surgical revascularization would significantly change how treatment decisions are being made. Gait variability potentially gives physicians an objective method to guide treatment decisions. Collectively, this work progresses treatment practice to ensure only patients who will significantly benefit will undergo invasive surgical procedures.